rs200716018

Variant names:

• chr2-178530049-T-C
• rs200716018
• NM_001267550.2:c.106442A>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):​c.106442A>G​(p.Lys35481Arg) variant causes a missense change. The variant allele was found at a frequency of 0.000161 in 1,611,666 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00011 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00017 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:11 B:3
• Conservation: PhyloP100: 5.47
• Publications: 2 publications found

Genes affected

TTN (HGNC:12403): (titin) This gene encodes a large abundant protein of striated muscle. The product of this gene is divided into two regions, a N-terminal I-band and a C-terminal A-band. The I-band, which is the elastic part of the molecule, contains two regions of tandem immunoglobulin domains on either side of a PEVK region that is rich in proline, glutamate, valine and lysine. The A-band, which is thought to act as a protein-ruler, contains a mixture of immunoglobulin and fibronectin repeats, and possesses kinase activity. An N-terminal Z-disc region and a C-terminal M-line region bind to the Z-line and M-line of the sarcomere, respectively, so that a single titin molecule spans half the length of a sarcomere. Titin also contains binding sites for muscle associated proteins so it serves as an adhesion template for the assembly of contractile machinery in muscle cells. It has also been identified as a structural protein for chromosomes. Alternative splicing of this gene results in multiple transcript variants. Considerable variability exists in the I-band, the M-line and the Z-disc regions of titin. Variability in the I-band region contributes to the differences in elasticity of different titin isoforms and, therefore, to the differences in elasticity of different muscle types. Mutations in this gene are associated with familial hypertrophic cardiomyopathy 9, and autoantibodies to titin are produced in patients with the autoimmune disease scleroderma. [provided by RefSeq, Feb 2012]

TTN-AS1 (HGNC:44124): (TTN antisense RNA 1) This gene encodes a non-coding RNA transcribed from the opposite strand to the titin gene. [provided by RefSeq, Aug 2016]

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.16418725).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001267550.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	NM_001267550.2	MANE Select	c.106442A>G	p.Lys35481Arg	missense	Exon 359 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.101519A>G	p.Lys33840Arg	missense	Exon 309 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.98738A>G	p.Lys32913Arg	missense	Exon 308 of 312	NP_596869.4	Q8WZ42-11

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	ENST00000589042.5	TSL:5 MANE Select	c.106442A>G	p.Lys35481Arg	missense	Exon 359 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.106286A>G	p.Lys35429Arg	missense	Exon 357 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.106166A>G	p.Lys35389Arg	missense	Exon 357 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.000105 AC: 16 AN: 152196 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000221

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000405 AC: 10 AN: 247170 AF XY: 0.0000373

Gnomad AFR exome AF: 0.0000647

Gnomad AMR exome AF: 0.0000294

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000623

Gnomad OTH exome AF: 0.000167

GnomAD4 exome AF: 0.000166 AC: 243 AN: 1459470 Hom.: 0 Cov.: 32 AF XY: 0.000152 AC XY: 110 AN XY: 725848

African (AFR) AF: 0.00 AC: 0 AN: 33384

American (AMR) AF: 0.00 AC: 0 AN: 44254

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26072

East Asian (EAS) AF: 0.00 AC: 0 AN: 39602

South Asian (SAS) AF: 0.00 AC: 0 AN: 85470

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53376

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.000200 AC: 222 AN: 1111258

Other (OTH) AF: 0.000348 AC: 21 AN: 60290

GnomAD4 genome AF: 0.000105 AC: 16 AN: 152196 Hom.: 0 Cov.: 33 AF XY: 0.0000941 AC XY: 7 AN XY: 74356

African (AFR) AF: 0.0000241 AC: 1 AN: 41456

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.000221 AC: 15 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.000157 Hom.: 0

Bravo AF: 0.0000907

TwinsUK AF: 0.000539 AC: 2

ALSPAC AF: 0.00 AC: 0

ESP6500AA AF: 0.000277 AC: 1

ESP6500EA AF: 0.000123 AC: 1

ExAC AF: 0.0000248 AC: 3

EpiCase AF: 0.000328

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	3	1	not provided (4)
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J (1)
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)
-	1	-	Cardiomyopathy (1)
-	1	-	Cardiovascular phenotype (1)
-	1	-	Dilated cardiomyopathy 1G (1)
-	1	-	Early-onset myopathy with fatal cardiomyopathy (1)
-	-	1	Myopathy, myofibrillar, 9, with early respiratory failure (1)
-	1	-	not specified (1)
-	-	1	Tibial muscular dystrophy (1)
-	1	-	TTN-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.098
BayesDel_addAF	Benign	-0.28	T
BayesDel_noAF	Benign	-0.45
CADD	Benign	17
DANN	Benign	0.74
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.0026
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.80	T
M_CAP	Benign	0.017	T
MetaRNN	Benign	0.16	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.57	N
PhyloP100		5.5
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-1.6	N
REVEL	Benign	0.14
Sift	Benign	0.089	T
Polyphen		0.16	B
Vest4		0.29
MVP		0.21
MPC		0.087
ClinPred		0.19	T
GERP RS		5.8
Mutation Taster		=93/7	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs200716018; hg19: chr2-179394776;